read choosed file cotent

It sounds like you're using the Dropbox Chooser with a "direct" link type to access the file data for the chosen file. 

I see that you already have the Chooser part working, and you're able to retrieve the file data from the returned link. What you do with the data from there is up to you, but note that the Dropbox link will just return the raw data for the chosen file. 

In this case, that will be the raw .docx file data. The .docx file format isn't plain text though, so it won't be directly human readable. You may need to use some third party library for reading the docx format and getting out whatever information you're looking for.